Pay-station telephone system



Jan. 12 1926. 1,569,623

B. G. DUNHAM v 15AY- STATION TELEPHONE sarswxm Filed August 1. 1925 4 Sheets-Sheet 1 (HI/en for: Ber) 6. flan/1am by W r? Jan. 1 2 .1926.

B. G. DUNHAM PAY STATION TELEPHONE SYSTEM Filed August 1. 1923.

4 shets sheet 2 Bar) 6. Dun/1am B. e. DUNHAM v PAY smxou TELEPHONE svsmn Jan. 12 192s. 1,569,623

Filed August 1. I923 4 Sheets-Sheet 3 g Q D Hill. IIIHP B? 6'. Bun/4am fly v In var/for.-

4 She ets-Sheet 4 B. G. DUNHAM PAY STATION TELEPHONE SYSTEM Filed August 1.

\NS 2% Q ii'lLll! Jan. 12 1926.

Patented Jan. 12, 1926.

Nl' 'l ()FF I BERT G. mini-reunion irAwrnonnn, nnv-I. annsEY, assrenon 'rowns'rnnnnnno'rnrc COMPANY, rnconronn'rnn, or new YORK, n. Y., A oonrona'rron on NEW YORK.

I rAY-sTA'rIon TELEPHONE SYSTEM.

Application rua August 1, 1923 Serial in. 655,028.

To all whom it may concern:

Be it known that I, BERT G. DUNHAM, a citizen of the .United States of America, residing at Hawthorne, in the county of Passaic, State of New Jersey, United States of-America, have invented certain new and useful Improvements in Pay-Station Telephone Systems, of which the followingis a full, clear, concise, and exact description.

This invention relates to automatic telephone systems and more particularly to pay station automatic telephone systems In such systems means is usually providedto enable the calling subscribers to select an operators position onspecial calls, such as toll'calls.

- The object of this invention is to provide a circuit arrangement which automatically functions upon the breaking down ofthe connection to dispose of the coin or coins deposited in the calling line coinbox if the operator fails todisp-ose of them before the connection is released.

In accordance with this invention the operator'is provided with means for impressing current upon'the calling line selectively to actuate the coin boX magnet, and additional means is provided associated with the trunk taken for use bythe calling party which means is automatically actuated duringthe breaking downof the connection to apply current to the calling line to actuate said magnet to dispose of the deposited coin or coins in case the operator has failed to do so. In the present embodiment in such cases the coin is automatically refunded to the calling subscriber. This isthe preferred arrangement owing to the relatively large number of calls made to the special positions and for which no charge is to'be made.

Referring to the drawings,

Fig. 1 shows a calling line, a line switch and the coin control circuit; Fig.2 shows a secondary line switch, a selector, and a called line; Fig. 3 shows a trunk leading from one of the levels of the selector to the operators position, and Fig. 4 shows the equipment at said position for enabling the operator to select the trunk used. by the calling subscriber and to control the disposition of the deposited coins thereover.

' The invention will be most readily understood from a detailed description of the nection.

- of the line switch which causes the line switch operations involved in settingup a con-J A 7 Upon the removal of the receiver at the l a calling SIJbStEIlJlO11,l3l16 relay 101 of the primary line switch PLS individual to the call to seize the preselected trunk by operating the set of springs in the well knownjrnanner,

as shown and particularly described for'example in Patent No. 1,304,369, to A. J. Ray of May 20, 1919. The calling line is now extended to the trunk circuit, whereupon relay L is operated as follows: free pole'of battery, contact 104 of relay Y, conductor 105, contact 106 of relay S, conductor 107 contact 198 of relay N N, resistance 1 87,conductors 109,110,, the inner right armature and back, contact of relay B, lowerarmature and back contact of relay A, ring conductor 165 including contacts-162, 163 of the line switch, the telephonic loop at the calling substation, tip conductor 164, including springs 166, 167 of the line switch, upper armature'and back contact of relay A, left armature and back contact of relay B, re-

tardation coil'188, relay L, outer left ar- 7 mature and back contact of relay .N N to ground. Rela L closes a circuit for the cut-off winding 107 of the line switch to hold the line switch set before the circuit for the'pull down winding 102 is opened as the line relay 101 releases. The circuit for the cut-off winding is as" follows:.

ground, left armature and front contact of relay L, conductor 108, outer right armature and back contact of relay H H, conductor 199, contact 1100f relay N N, conductor 146,

release or sleeve conductor 125, springs 112,

113 cutoff winding 107, free pole of battery.

hen the ated and closed springs 114, 115 the follow ing circuit was closed to operate the secondary line switch SLS to' seize an idle first selector, grounded spring 115, spring 114,

secondary line switch holding conductor 116, outer left armature and back contact of relay H H, conductors 117 202, pull down coil 2080f the secondary line switch, conprimary line switch PLS operl tact 204, conductor 205, slow relay 206,. to '2 free pole of battery. The secondary line switch SLS in operating closes a locking circuit for itself, including its windings 207, 203 in series and contact 208, to grounded holding conductor 201. 1

Relay L,in attracting its left armature, operatesslow to release relay N, which operates relay N N. Relay N N in attracting its outer left armature removes the shunt from" armature substitutes relay RT for resistance 187 in the calling line circuit. Relay RT is thus connected to the ring side 165 of the calling line.

Relay RT is marginal and will not operate in the line circuit due to the high resist ance 118 and relay L. Resistance 118 is normally short circuited, its short circuit being removed when relay N .N operates to increase the margin of operation of relay RT.

The circuit'remains in this condition until 7 the calling party inserts a com 111 the coin box. The coin box may be of the type shown and described in Patent 1,0 3,219 of November 5, 1912, to O. F. Forsberg. As shown and described in detail in said patent the deposited coin causes the closure of contact 120 to ground the tip side of the line 164 and, since the receiver is now removed from its hook, this ground is also connected to the ring side of the line 165. The application of this ground closes a shunt about relay L and the high resistance 1.18, whereupon the marginal relay RT operates over a circuit including the ring side of the line 165, the calling substation receiver hook, and the ground closed by contact 120 of the coin box.

Relay ET in operating, energizes relay S over the following circuit: battery, armature and front contact of relay RT, conductor 121, relay S, conductors 122,128, outer left armature and front contact of relay N N to ground. In attracting its outermost left armature, relay S connects conductor 116 to conductor 11? independent- I ly of the outer left armature and back contact of relay H H. In attracting its middle left- .armature, relay S provides a dlrect path to ground through coil 188 from the tip side 16 1- of the line short circuiting relay L and resistance 118. Relay L releasing, opens the circuit of relay N which is slow to release. In attracting its innermost left armature, relay S connects the impulse relay R to the ring side165 of the line. in attracting its inner right armature it removes relayRT from the calling line circuit and locks itself to grounded battery at a normal contact of relay Y and to the grounded sleeve or release conductor 124.

This conductor was grounded when the secondary line switch seized the first selector in the well known manner. The locking circuit of relay S isas follows: free pole-of battery, contact 104: of relay Y, conductor 105, inner right armature and front contact of relayS, relay S, conductor 122, grounded sleeve wire 12 1 In attracting its outer right armature, it' operates relay H H and slow relay H. The circuit forrelay H H leads over conductor 176 and-theouter right armature of relay B conductor 189.;

Relay H then locks itself over conductors 174, 176, outer right armature andback contact of relay B, conductor 189 to battery ,at its own armature andfront contact. Relay H H being connected to conductor 18 9is.

also, held up by the armature of relay H.

Relay H H} in attracting. its inner right armature, connects grounded conductor 148 grounded conductor 148 is however extended to the sleeve conductor 125 by relay H H before relay N, which isslow, releases.

The calling party now operates his sender in accordance with the first digit of the wanted number, andon the return of the sender, to its normal position, the following circuit including the impulse relay R is interrupted: free'pole of battery, relay R, conductor 126, inner left armature and front contact of relay S, conductors 127, 128, inner right armature and back contact of relay B, lower contacts of relay A, the ring side 165 of the line, the substation loop, the tip side 164, of the line, theupper back contacts of relay A, leftarmature and back contact of relay B, retardation coil 188 to ground at the middle left armature of relay C. The ground connected to the tip side of the line at spring 120 does not interfere with this impulse circuit. Upon initial operation of relay R before the sender was operated, it closed at its lower front contact a circuit for sloW-to-operate relay D which in operating extended the front contact of relay R to energize relay I) D which connected the incoming and outgoing ends of the tip and ring conductors together, these conductors including a pair of condensers 129, 1230. Upon the first retraction of the armature of impulse relay R, due to the' sender interrupting the line, relay D D llU instantly retracts its ii-matures, disconnecting the incoming tip and ring conductors from the outgoing tip and ring conductors.

Relay 1) is constructed and arranged so that it will not again attract its armature while the impulse relay armature is vibrating. RelayD D thus remains inert-during this period to maintain the condensers disconnected from the outgoing ends of the tip and ring conductors to prevent interference with the character of the impulses, by the discharge of the condensers.

Only parts of the switches S and C are shown, since these switches are well known. They may be of the type shown in Reissue Patent No. 13,901, issued April 13, 1915, to F. Newforth, Jr.

Assuming that the selector S and preceding switches have been set and the calling line extended to the connector C, the impulse relay 210 (Fig. 2) of the connector C. is

" operated over the following circuit: free pole of battery, right winding of relay 210, normal contact of relay 211, conductor 233, ring conductor 212, multiple terminal 213 and brush 214 of the selector S, ring conductor 215, secondary line switch contact 216, ring conductor 132, (Fig. 1) contact 133 .of relay J, conductor 134, upper armature and front contact of relay R, conductors 135 and 136, retardation coil 181, polarized relay P, tip conductor 139 including contact 140 of relay J, tip conductor 195, contact 226, tip conductor 227, brush 228, terminal .229 of selector S, tip conductor 230, conductor 231, outer normal contact of relay 211, left winding of relay 210 to ground. Relay 210 at its front contact operates slow relay 240, which interposes a break in'the circuit of release magnet 241 and grounds the sleeve wire 245 in the well known manner.

The operations of setting the connector need not be described since they are well known and form no part of this invention. The impulse relay R, which is in circuit with the sender, at its upper armature and front contact controls the circuit of the connector impulse relay 210.

When the connection has been built ii to thecalled line,vthe response of the called party operates relay 211 which reverses the flow of current in the tip and ring conductors leading back to the coin collect circuit. Relay P, which is polarized, thereupon operates, closing a circuit for relay C'to prepare a circuit including the coin collect source 0 C and the calling line. The circuit for relay C is as follows: free pole of battery, relay G and-its normal upper contact, conductor 1.42, armature and contact of relay P,

conductors 192, 157,146 to the release conductor 125, which is grounded at the inner right armature of relay H H. Relay C in attracting its. armature 155. locks itself to conductor 146. over the following. circuit: due to the opera- Relay J is also energized.

tion of relay P; free pole of battery, resist- I ance 184, relay J ,conductor 150, armature of relay K, conductor 142, contact and arma-,

ture of relay P, conductors 192, 157, 146,,to

0, to the grounded sleeve conductor- 124.

Relay A extends the tip and ring conductors leading from the primary line switch to the tip and ring conductors 139, 134, cutting off the bridge containing the impulse,

relay R and retardation coil 188. Relay R V in releasing its upper armature removes the bridge containing the impedance coil 181 from across the talking conductors. V

The subscribers may now converse. Talking current is fed from the connector. to the calling line over the following circuit: free. pole of battery, 7' right winding of relay] 210, outer armature and front contact of relay 211, conductors 231, 230, terminal 229, brush 228, conductor 227, contact 226, conductor 195, contact-159, of relayJ, conduc tors 134, 160, 161, lower armature and front contact of. relay A. contact springs 162, 163, conductor 165, through the substation talkset, conductor 164, springs 166, 167, conductor 164, upper armature and front contact of relay A, conductor 168, relay P, conductors 139, 170, armature 169 and front contact of relay J, conductor 132, contact 216,

conductor 215, brush 214, terminal 213, conductors 212, 233, inner armature and front contact of relay 211, left winding of relay 210 to ground. Current is fed to the called line over the windings of relay 211.

When the calling party replaces his receiver, ground is removed from the sleeve conductor 245 by the release of slow relay 240, which causes the connector and selec-v tors to restore. The removal of this ground also releases relay S, which in releasing its outer left armature releases the secondary line switch SLS. Relay S at its outer right.

armature and back contact also closes a circuit for relay Y as follows: free pole of battery, outer right armature and back contact of relay S, conductor 171, relay Y, contact 172 of said relay, conductor 173, inner liO left armature of relay H H, lower contact of the constantly operating interrupting machine I to ground, when the lower. contact 'is'closed by the cam of the machine;

Relay Y in'operating, locks itself to ground-.' ed conductor 148 by closing its contact 177'.

When. the interrupting. machine: IneXtF closes its upper contact, aniinpulse of current is delivered to coin current applying relay B over the inner leftarmature and front contact of relay Y. This relay in attracting its armatures impresses positive current of preferably 110 volts from the collect source C C to the calling line to operate the polarized magnet PR in the coin box at the calling station to collect the coin. This circuit is as follows: free pole of source C C, conductor 1 78, lower armature and front contact of relay G, relay 190, conductor 179, left armature and front contact of relay B, upper armature and back contact ofrelay A, springs 167, 166, tip conductor 16%, contact 120, polarized magnet PR to ground. Relay A released when ground was removed from the sleeve conductor at the connector. The polarized magnet PR operatesto collect the coin as shown and described in said Forsberg patent. In operating, magnet PR locks itself to ground by closing contact 119 and then releases the coin, opening contact 120. Due to the closure of contact 119 the magnet PR remains operated as long as the coin current is applied, as shown and described in detail in said Forsberg patent. In case the first impulse from the interrupt ing machine fails to cause the collection of the coin, additional impulses are sent and the release of the primary line switch PLS is held up in the following manner: when the relay B operated, in attracting its outer right armature it opened the locking circuit previously traced for slow relay H, but before the relay H can (lo-energize, a substitute circuit is closed by the armature of relay 190 which operates in the coin current circuit in series with the polarized magnet PR. Relay H as pointed out holds up relay H H which at its inner right armature is maintaining ground on the sleeve conductor leading to the holding winding 107 of the primary line switch. Thus these two alternate circuits maintain relay H operated until the ground at the substation is removed. As long as relay Y remains operated, lamp 180 lights before an attendant, who will investigate in case the apparatus does not' function properly.

Assuming, as in the normal case, that the polarized magnet PR functions properly, the second time the relay B operates from the interrupter I no ground will be present at the substation and the relay 190 will fail to operate and the substitute circuit for relay H at the front contact of relay 190 will not be present when relay B opens the other circuit at its outer right'armature and back contact when it is next operated from the interrupter I. Relay H accordingly releases, releasing relay H H. Relay H H in retracting its inner right armature re.- moves ground from. the sleeve conductor leading to the holding winding 207 of the line switch SLS, resulting in the release of the same. i

In case the called party has not responded,

polarized relay P would not have shifted its;

armature and relay C would have remained inert. At its lower armature, this relay would have connected negative current from the 110 volt coin return source CR to the calling line to cause the polarized magnet TR to refund the coin, lock up" to ground at contact 196, and open contact 120. 7 When the operating current ceases, magnet PR releases, opening contact 196 whereupon the primary line switch would release as described.

Certain lines called free lines are segres gated upon connectors which do not reverse the current flow in the calling line when the called party responds. on such calls, battery is fed to the calling line over the impulse circuit previously traced,the relay B being balanced by the retardation coil 188, the condensers 129, 130 separating the calling and called ends of the circuit.

The retardation coil 181 is provided in these calls to prevent short circuiting the voice currents.

Upon disconnection in this class of calls, inasmuch as relay G is not operated, the coin is refunded as in the case of unsuccessful calls.

Resistance 182 is connected to ground at one end and to the condensers 129, 130 at the other end over normal contacts of relay D D. The other terminals of these condensers are connected over normal contacts of relay A to the armatures of relay B over which the relatively high potential coin current flows. Thisarrangement is for preventing the burning of the contacts of. relay B when the high voltage coin current is cut off by the interrupter I releasing relay B. i

The ground applied by the polarized magnet PR is connected to the tip side 16a of the line and the ground through the relay 210 at the connector is also normally applied to the same side of the line. However, when the relay 211 is operated when the called party answers, battery is connected to the tip side of the line and to prevent the change from affecting the release operation, relay J which operates due to relay 211 operating is provided to restore the original connections.

More particularly, when the calling party is the first to restore the receiver inasmuch as relay J is held up from ground on the sleeve wire 124, no circuit is closed through the right winding of relay 210, for connecting battery to the tip side of the line and the coin ground, does not prevent the release by holding up relay 210. Relay 210 therefore releases, opening the circuit of the usual slow relay 2 10. The release of.

the'slow relay energizes the release magnet 214 which releases the connector and the release of the slow relay removes ground from the sleeve conductor 235, which releases the selectors. before the coin collecting operations are completed and inasmuch as the ground on the release Wire 125, to which relay J is locked, cannot be removed until these, op erations are completed the circuit referred to from the ground in the coin box to the right Winding of j relay 210 is not closed.

When the called party restores first, relay 211 releases and reverses the current flow in the calling line. In this event relays J and K cooperate to prevent this condition from affecting release. When the relay J operated upon the response of the called party, it caused relay P to restore and closed a circuit forrelay K by attracting its armature 183 this circuit including the grounded sleeve wi're'125. Relay Kat its right armature in operating prepares a circuit to shunt relay J. When the called party replaces his receiver and reve'rses'the,

current flow inthe calling line, relay P operates and shunts out relay J over resistance 184, conductor 185,7armaturearid front contact of relay K, contact of relay P, conductors 192, 157, 146, 147,"inner right armature of relay H H to grounded conductor 148. Relay J releases before relay K closes its back I contact, thus preventing relay J from again operating. Relay J restores the original connections-to the tip and ring conductors so that the ground in the coin box is now connected to the tip side164 of the line to which the grounded side of relay 210 is connected. Thus when the call- ,ing party restores his receiver, no circuit could be maintained closed from the coin ground to the Winding ofrelay 210to which the free pole of battery is connected. Thus release is not prevented.

Relay P is located-in thetip side of the line rather than the ring side 'so'that if the called party hangs up immediately after the calling party and releases relay 211 thus reversing battery to the calling party before the slow relay in the connector'has time to release and remove the ground from thesleeve wire which is holding up relay S, relay P will be operated when relay 211 releases over a circuit from the free-pole ofbattery through rightwinding of relay 210 to the coin ground, thus short circuiting relay J as described, which reconnects the coin ground to the grounded side of relay 210 and reconnects the side of "relay 210 connected to the free'pole of battery to the ring side of the line which is open at the switchhook. Thus release is not interfered with.

The operation involved in setting up con nections' without the aid of the operator The selectors release having been described, a connection in; Q

dial to transmit the proper number of impulses causes the selector S to be. raised to the level containing the trunks leading to i the operators position whereupon the se lector tests'for and seizes an idle trunk-T,

(Fig. 3) in the well-known manner.

When this trunk is selected a loop including the armature; and front contact ofthe impulse relay'R' (Fig. 1) is presented acrossthe tip and ring of the trunk T and' relay 300 operates, closing the circuit I for operating slow 'to release relay 301, which at its armature 325 places ground upon the release trunk 346 and terminal 362 through the winding of the tone transformer 302 to hold thepreceding switches set in the well-known manner. Relay 300 at its armature 323 also closes' a circuit from battery through relay 303 onto the ring side of the trunk\vhich'terminates inthe manual oflice, thusgcompleting the circuit for operit ating the loop relay 347 at said ofiice which causesa lamp 348 to light beforethe operj ator, as a signal to her thatth'e trunk has been selected. The return'for, this circuit is over the tip conductor342 to ground through the right winding of relay 303 and 1 secondary of coil 302. Itelay303 is'marginal and will not operate in series with ice I relay 347. Relay 301 at its armature 326 closes the interrupted generator 306 onto the ring side-of the incoming trunk by Way of armature 329 of relay 307 which serves to return a ringing tone to the callingsubscriber. When the operator insertsplug 400 into jack 314 marginalrelay 303 operates due to low resistance relay 403 being substituted for relay 347. Relays 401 and 349 operate also, the former preparing thelamp circuit and the latter cutting off loop relay.

347. Relay 303 at'its armature 321 closes the circuit for operating relay307, which looks to the grounded release trunk 346 at armature 331. Relay 307 at said arma ture removes the short circuit from around the low winding of the tone transformer 302.

This short circuit was for the. purpose off preventlng the class of servlcetone from bey ing returned to the calling subscriberat the sametime as the ringing tone. "Relay 307 v at armature 329 removes the ringing tone from the trunk and prepares the circult r'or relay"308'atarmature330. Relay 307 will remain operated until the trunk has been released. The calling subscriber'is class tone coil CT at the'line switch by its primary causes tone to be impressedupon the release trunk through its secondary 197 if such line is restricted in the class of calls it.

makes as shown and described in British Patent No. 15,133 of 1911 This tone is re peated by the tone transformer 302 to the tip side of the trunk T, and the operator in throwing her listening key 422 will detect this tone, which serves to indicate to her the class of service to which the calling subscriber is entitled. In order to remove this tone theoperator depresses a tone :rcinoval key in the cord (not shown) whichcauses a nomentary interruption of the trunk loop circuit, and relay 303 will momentarily restore. Relay 309, which was operated by relay 303, is a slow releasing relay and will not restore in the interval that relay 303 is released. Relay 303 in releasing its armature 321 closes a circuit for operating relay 310 from ground at armature 3131.. Re lay 310 operates and locks to ground at armature and front contact of relay 309. Relay 310 short circuits the secondary winding of the tone transformer, which causes the tone to be removed from the trunk T. Relay 310 also extends the tip and ring of the subscribers transmission circuit to the tip and ring of the trunk into which the operator has her plug 100x11 the operator, after having removed the tone desires to cause it to be replaced for the purpose of checking, she removes the plug of her cord from the jack for an interval long enough for relays 303 and 309 both to restore. Upon reinserting the plug, relay 303 will operate, closing the circuit for again operating relay 300, but before relay 309 can clos its front contact,

' to which relay 310 was locked. relay 310 will restore, and therefore cause the tone to be replaced on the trunk which tone can again be removed previously described.

Referring now to Fig. 4. When the operator who we will assume is a toll operator, has built up the connection over plug 405, jack 406 and the intervening trunks to the called line 407, has found the line idle, has applied ringing current, and the called sub scriber at station 407 has responded she requests the calling party to deposit the required coins in the coin box. The coins, in dropping in the coin box, strike bells which, in the well known manner, inform the operator of the character of the deposited coins. Theoperator then picks up a plug I s-10 at her position and inserts it in a collect jack J 10 and by means of the dial Dl0 and an automatic switch shown in Fig. 4 selects the trunk T shown in Fig. 3 which is multipled to this automatic switch at 1020, 1021. If the plug is inserted into the collect jack a relay H10 operates to prepare a circuit from a source of current of 110 volts positive polarity to the selected line to operate the polarized magnet in the coin box to col.- lect the coins. If, on the other hand, the plug P-10 is inserted in the refund jack R-10, relay H+ 10 is not operated and con sequently negative current of 110 volts is impressed upon the called line to operate the polarized magnet in the coin box in the opposite direction to refund the coins. The upper armature 1023 of the relay H.10 in its attracted position closes a circuit from a tone source 1022 of one character to the operators head set whiclrinforms her that positive impulses of current are being trans mitted to the called line. This armature in its retracted position gives a diii'erent tone to the operators head set from tone source 1027 to indicate to her that negatiye inipulses are being transmitted to the called line. The operator is thus informed whetherthe coin collect circuits are functioning properly or not. As shown in the said li orsberg patent, when the polarized relay operates in either direction it disconnects itself from ground, whereupon the relay H10 in the coin current circuit ceases to operate to transmit this tone thus informing the operator that the polarized magnet has functioned. the plug P10 from. the jack whereupon the automatic switch of Fig. 1- is restored toits normal position. v

More in detail, after the subscriber has deposited the required coins which are to be collected, theoperator at position P picks up her plug P-10 (Fig. 4) and touchin the tip of the plug tothe tip of the jacr J-10 and finding the same idle,'she inserts it into said jack. Theinsertion of the plug P--10 closes a circuit for relays E-91 and E--99 over the sleeves of the plug and jack, and relay .E-91 thereupon operates the signals which the multiples of this jack appear. Relay 11 1-99 in operating disconnects thc busy test circuit and connects the dial D-10 to the tip of the plug. Battery on the sleeve of the plug causesthe multiples of'the seized trunkto test busy at the otherpositions. The operator knowingthe number of the trunk T shown-in Fig. 3 because of the designation on the jacks themselves or the designation strips associated with the. jacks now rotates herj dial to set the automatic switch shown in Fig. 41 to connect with the multiples 1020, 1021 .of the used trunk T which appear in this switch. The automatic switch of Fig. 1 and all apparatus shown at the right of the dotted lineare located at the automatic oflice, that is to say in the same oflice with the selector of Fig. 2. The equipment shown at the left of the dotted line of Fig. 4 is located at the oliice where ,jack 314 is located, thatis at the manual ofiice. The insertion of the plug P10 energizes the impulse relay A-10 over the following circuit: free pole of-battery, resistance 1050, impulse springs of the dial, armature and front contact of relay She thereupon withdraws 1002 and 1003 atthe positions in jack 5, 10, conductor 1005, conductor 1.006, upper normally closed contact of off normal switch 100?, conductor 1008, impulse relay A1 0, conductor 1 009, conductor 1010, ring of the jack J10, ring ofthe plug,P10 to ground. The impulse relay in operating energizes the usual slow to release relay B10. "Relay B10 in attracting its'outer right armature closesa circuit for the upper Winding of relay H10. 'This winding of relay ll--10 when energized is not suflicientlyjstrong to cause the/relay to operate but is sufficient to cause relay H10 to "switch 100?, slow relay C-10, vertical magnet 1013 to free pole of battery.- The, first 110 volts negative currentto connection,

operate when the current through the lower winding 1s m the right'direction to aidthe current 511 the upper winding; lower. winding of relay H10 will not cause the operation oftherelay H 10, [when the current [lowing the upper winding opposes-that: flowing 111 the lower winding; 'lhe'lower winding however is shunted while the switch shaft is in its normal position.

Upon theireturn movement of the dial the impulses aretransmitted'to the impulse relay 'A10.u Upon each retraction of the armature of this relayan impulse is transmitted over'the followingcircuit to'the vertical magnet-1013 of the'switch, ground, armature and back contact of relay A 10, inner; armature front jcontact of relay B 'lO, lower normally closed contactof off normal step of the switch operates'the oftnormal switch 1007 which removes the short circuit from around the lower winding ofthe relay 1-1-10, whereupon relay Hp1'0 operates and shifts the armature 1012 from its nor-' mal connection with the refundisource of with the collect-source of 110 yolt's'positive current. i '1 Upon the first vertical step 'the'off normal 1 switch 1007-operatesand the succeeding impulses then pass by way of contact 1015 and the armature and front contact'of slow relay C 10. 'Upon the cessation of the impulses the slow relay C, 10 releases preparing a circuit for the .rotary'ma'gnet 1016 closed upon the return of the-dial for the units impulses. The impulses now pass fromthe'bacl; contact ofthe stepping relay A-10, inner armature and front contact of 'relay"B10," contact 1015, armature and jback of relay'10,-slow relay E'10, outer right handarmature' and backcontact of relay D 10, rotary magnet 1016 to free pole of battery. Relay E 10 in attracting its outer left armature energizes relay D10 whichin attracting its left armature locks up to; theouter right armature of relay -Bl0. --Relay E'- 10 in attracting its inner ,5 left'armatu're operates relay F10." Relay o E10 in attracting its right armature connect-s the rotary magnet in the stepping cir-- cuitindependently of the outer right armature of the relay D10.' Now when the units impulseshavc all been transmitted the, slow relay E'10, after a slight interval,

releases. The retraction of its inner "left armature opens the circuit-through the left windingjof relayil? "-10; If at this time the interrupter 1017" on a metallic segment relay F1 0 will be held up by its armature. When the interrupterpasses to thenext insulating segment relay FelO releases and :its armature connects rel G10' over the inner right armature and front contact of relay D+10 to the interrupting machine 7 1017. 'F-10 is providedfto insure that the first It will be apparent that the relay impulse toa'elay G510 will be a full the.

Thebrushes 1018 and101'9,"beingnow in contact with multiples 1020 andf1021ofthe trunk'T shown in 3, upoirflthe first engagement of the interrupting machine brush with the metallic segment after relay 1 -10 has" released, an impulse is transmitted to the relay Cir-10, which" in attracting v its armature connects the source of collectcu'rrent byway of the brush 1018, multiple 1020, conductor 341, 3, relay 31"1"and toground. Relay 311 in turn operates relay"312j Relay 312'in operating reyersesthe battery toward the calling subscriber, which'serves to cause the pay station repeater F igrlIto prepare to control the disposition of the coin IasdesCribe'd in" detail. At the iend 'ofthe period, relayy3ll restores,'but relay 3121s slow to release andbe'fore it can restore, relay 313 is operated and locks to the" release trunk. The next'period of coin controlcurrentcauses relay 311 to operate and the coin control current passes toward the calling subscriber by wayof front contacts of relays 313 and 812, this circuit includingswitch I hook springs of the substation telephoneset contact. 120 in the coin box, 'polarized1magnet PR of the coinbox to groundf Current will flow "through relay J "-10 (Fig; 4:) to ground at the coin box each time relay G10 operates untilthe coins have been collected in'case they are not-collectedupo11 rent is being sent out to the line. This cir-i cuit leads from a'source 1022 overthejfr o nt contact and'armature 1023 of the relay Hl0, armature and front contact of relay 'J'10, condenser 1069, brush 1019, multiple 1021, conductor 3 10 Figslifland3, which multiple is "connected to the ring conductor of the trunkfrom whence it is transmitted to the operators head set. The operator, ceasing to hear the tone knows that the coins have been collected and pulls out the plug P 10. If the polarized magnet fails to vcollect the coins or if the coin box fails to function properly for some reason or other the contact 120 remains closed and the repeated impulses of tone will infornrthe operator of this condition and she willpullout the plug and report the line. The removal of the plug causes the release of the impulse relay Al0 and slow relay B10 which closes the following circuit for the release magnet Jfl025; free pole of battery, magnet Jl025, upper contact ofthe off normal switch 1007, inner armature and back contactof slow relay 13-10 armature and back contact of relay Al0 to ground. The release magnet restores ,the switch and the switch, upon reaching its normal position, restores off normal switch, 1007.

If the operator had plugged into the refund jack It-10, if for any reason the coins wereto berefunded, the current in the lower winding of relay H10 would oppose that flowing in the upper winding and relay H,10 would not operate when off normal switch 1007 opened the shunt about the lower winding. Consequently the armatures of relay H10 would have remained re" tracted, the armature 1012 connecting the refund source of negative current to the called line to operate the polarized magnet PR in the opposite direction to refund the Armature 1023 at coins to the subscriber. its contact would connecta source of refund tone 1027 in circuit with the operators head set each time the relay J10 operated. As

in the case where the coins were collected,

the toll operator ceasing to hear refund tone impulses knows that the coins have passed through the box and she removes the plug from the refund jack. It is of course understood that the tone sources 1022 and 1027 are of different character for example, the refund source can be 460 pulsations per second and thecollect source 150 pulsations per second. 7

When the calling party hangs up his receiver, relay 300 will restore and will transfer the ring of the trunk from battery 7 through the low resistance winding of 303 to battery through the high resistance 339 and high resistance relay 308. The replacing of the low resistance battery feed withthe high resistance battery feed causes supervisory relay 403 in the cord circuitto release to light lamp 402 to signal the operator that the calling party has hung up his receiver, whereupon she removes the plug 400 from jack 314 which releases relay 308. This relay in retracting its armature .opens the circuitof relay 309 which in turn releases slow relay 301. This relay in retracting its arwith, switchesand trunks for extending connecmature 325 removes the holding ground from the release trunk which causes the restoration of the automatic switch as described. 7 u i If a refund is to be made for the call the operator will not actuate her dial D-l0 to select the trunk T but merely withdraws the plug {100 from jack 31a and assuming the calling party had replaced his receiver, the coin collect circuit of Fig. 1 would then function to refund the coins automatically exactly as described in detail in the case where the calling party replaced his receiver after failing to obtain a response from the.

called party.

From the foregoing it is apparentthat by virtue of this invention the operator is re lieved of considerable work in refunding coins, such work being performed automatically by the central ofiice equipment.

What is claimed is:

1. In a telephone system, telephone lines,

check controlled devices associated therean operators POSLiSlOIl, automatic tions from said lines ,tosaid position, means controlled from said position'for rendering an established connection metallically conconnection metallically continuous between a calling line and said operators position, means controlled bythe'operator for operating the magnet of a calling line coin box over StldCOIlIlBOtlOl'l to collect or refund a deposited coin, and means for automatically operating said magnet to refund the deposited coin in case the operator fails to do so.

3. In a telephone system, telephone lines, check controlled devices associated therewith, a repeater circuit, an operators position, automatic switches and trunks for ex tending connections from said lines through said repeater circuit to said position, a relay in said repeater circuit controlled from said position for rendering an established connection metallically continuous. between a calling line and said operators position, means controlled by said operator for governing the operation of said device of the calling line over said connectiomand means for automatically operating said device in case the operator fails todo so. i

4. In a telephone system, telephone lines, check controlled devices associated therewith, an operators. position, 1 automatic switches and trunks for extending connections from said line to said position, means controlledfrom said position for rendering an established connection metallically con tinuous between a calling line and said operators position, a plug and jacks at said operators position for governing the operation of the devices of said calling line over said metallicv connection, and means for automatically operating the device in case the operator fails to do so.

5. In a telephone system, telephone lines, coin boxes associated therewith, an operators position, automatic switches and trunks for extending connectionsfrom said lines tov said position, means controlled from said position for rendering an established connection metallically continuous between a calling line and said operators position, means controlled from said operators position for operating the magnet of the coin box of a coiling line to collect or refund a deposited coin over said connec tion, and means for automatically operating said coin box magnet during the taking down of said connection in case the operator fails to do so. u

6. In a telephone system, telephone lines, coin boxes associated therewith, an operators position, automatic switches and talking trunks for extending calling lines to said position, automatic switching means and special coin control trunks controlled from said position for selecting the talking trunk taken for use by a calling line, sources of current for operating the magnets of,

said coin boxes, means at said position for impressing current on the calling line via said special trunks to selectively operate said coin box magnet of the calling line, and means for automatically applying current to the calling line to operate said coin box magnet in casethe operator fails to do so.

7 In a telephone system, telephone lines,

coin boxes associated therewith, an operators position, automatic switches and current for operating the magnets of said coin boxes, means at said'posltion for impresslng current on said line via said special trunks to selectively operate the coin box magnet of the said line, and means fo automatically applying current to the said line during the breaking down of the connection to operate thecoin box in case the operator fails to do so.

8. In a telephone system, telephone lines,

coin boxes associated therewith, an operators position, automatic switches and trunks for extending calling lines to said position, automatic switches controllable I 'from said position and containing multiples of said trunks, sources of collect and refund current, means at said position for impressing current from either source on one of said calling lines via one of said last mentioned automatic switches, and means for automatically applying current tov said calling line during the breaking down of the connection to operate its coin box mag: net in case the operator fails to do so.

i 9. In a telephone system, telephone lines, coin boxes associated therewith, an operators position, automatic switches and trunks for extending calling lines to said position, automatic switches controllable from said position and containing multiples of said trunks, sources of collect and refund current, means at said position for impressing current from either source on one of said calling lines via one of said last mentioned automatic switches, and means for automatically applying current to said calling line during the breaking down of the connection to operatethe coin box magnet to refund the deposited coin in case the operator fails to do so. i

In witness whereof, I hereunto subscribe 95 my name this 30th day of July A. 1)., 1923.

BERT 'G, DUNHAM. 

